A rise in adolescent female aggression and violence has been seen over the past three decades, with little information available on this growing population. The Tennessee Self-Concept Scale 1st edition (TSCS-I), Life Styles Index (LSI), Carlson Psychological Survey (CPS), and Index of Religious/Spiritual Beliefs and Practices were used to examine personality traits of 26 delinquent and 81 non-delinquent females (ages 13-19). Data was gathered in a northern California juvenile hall and various community programs and schools. Due to an ethnic difference found between the delinquent and nondelinquent groups, ethnicity (White/non-White) was used as an additional independent variable. 2 x 2 (groups by ethnicity) ANOVA's were utilized revealing significant interactions for ten variables including: Identity, Behavior, Moral Self, Religion, Denial, Regression, Chemical Abuse, Thought Disturbance, Anti-social Tendencies, and Self Depreciation. Overall, results indicated that White delinquents in comparison to non-delinquents, have poorer self-concepts, utilize different ego defensives and have higher criminal behaviors. In contrast, non-White females, regardless of their delinquency status, were found to have more similar personality traits. Differences found in self-concept, ego defenses and criminal behaviors between diagnostic group and ethnicity adds to the understanding of personality functioning of female delinquent youth. Discussion of the clinical implications this research has on aiding the development of more effective prevention and treatment strategies for female youth..